We present super(12)CO(J= 110) observations of the high-redshift quasi-stellar objects (QSOs) BR 1202-0725 (z =4.69), PSS J2322+1944 (z = 4.12), and APM 08279+5255 (z = 3.91)using the NRAO Green Bank Telescope (GBT) and the MPIfR Effelsberg 100 m telescope. We detect, for the first time, the CO ground-level transition in BR 1202-0725. For PSS J2322+1944 and APM 08279+5255, our observations result in line fluxes that are consistent with previous NRAO Very Large Array (VLA) observations, but they reveal the full line profiles. We report a typical lensing-corrected velocity-integrated intrinsic super(12)CO(J = 110 line luminosity of L super('CO)=5 x 10 super(10) K km s super(-1) pc super(2) and a typical total H sub(2) mass of M(H sub(2)) = 4 x 10 super(10) M sub( )for the sources in our sample. The CO/FIR luminosity ratios of these high-z sources follow the same trend as seen for low-z galaxies, leading to a combined solution of log L sub(FIR) = (1.39 c 0.05) log L sub(CO) -1.76. It has previously been suggested that the molecular gas reservoirs in some quasar host galaxies may exhibit luminous, extended super(12)CO(J = 110) components that are not observed in the higher J CO transitions. Using the line profiles and the total intensities of our observations and large velocity gradient (LVG) models based on previous results for higher JCO transitions, we derive that emission from all CO transitions is described well by a single gas component in which all molecular gas is concentrated in a compact nuclear region. Thus, our observations and models show no indication of aluminous extended, low surface brightness molecular gas component in any of the high-redshift QSOs in our sample. If such extended components exist, their contribution to the overall luminosity is limited to at most 30%.